Dynamic Post Filter
This page shows the filter using the operator “IN AND”: Posts must have at least one tag in each of the selected groups.
The Meta Box appears only on post edit screens in the backend. You can test it here. (Log in with username and password “demo”.)
Multi-Group-Aware Tag Cloud
Below you see the tag cloud that comes as part of the free plugin. The difference is here, that you can use the same tag under multiple groups. See for example the tag “travel” under “Work” and “Countries”. When you click on this tag, you will see different posts, depending on the group where you click. The reason is that this tag was used in these posts with different groups.